We are spending a week in UK with rental car and wanted to add a day in Ireland. What would be the most cost-effective way to be able to drive in Ireland? Ferry the car or fly and rent another?? If flying is best option, any good idea for cheap car rates in Emerald Isle?

You're just spending one day in Ireland? That seems rather pointless, but that wasn't your question. Just renting for the day would be your best bet. The ferry is only worthwhile with your car if you're going for an extended period as it can be expensive for cars.

Thanks for your thoughts. We would LOVE to spend more time, but have a lot to try to squeeze in! Will look for good rates.

Meant to mention: it's much cheaper to rent by the week, so avoid chopping your UK rental into 2 small, expensive parts by either take your day in Ireland at the end or beginning of your trip, or just park your rental at the airport while you're in Ireland without turning it in.

I also want to apologize for my "pointless" comment. It always annoys me when people on here don't answer the question and instead get judgemental about someone's travel plans, and I went and did the same thing. You should have told me to shut up!

Yep, parking the rental is what we're going to do! The rental rates are high but how else to see stuff "off the path" Thanks for your followup, it was thoughtful.